SBIR Phase I: Preclinical Development and Mechanical Testing of a Load Transfer Implant (LTI) for Knee Joint Arthroplasty

This Small Business Innovation Phase I project is focused on a novel knee replacement technology that employs leading edge manufacturing processes that enable production of unique device structures designed to improve bone-device interaction and eliminate the need for revision procedures. This technology utilizes engineering principles such as load transfer and truss design to improve bone integration with a Total Knee Replacement (TKR) implant. Additive layer manufacturing technology, or computer aided fused titanium rapid prototyping, can be used to produce an innovative TKR implant that incorporates innovative web truss geometries for the bone interface component. It is anticipated that the web structure will provide improved initial fixation, reduce micro motion, and eliminate aseptic loosening. This project is designed to further optimize and measure the operating parameters and durability of the device through mechanical testing outlined in the FDA'S Guidance Document for TKR implants. Experiments will include fatigue testing, constraint testing, contact area testing, kinematic modeling and fixation testing. It is anticipated that this device design will represent a significant advancement in knee replacement technology that is substantially more stable and resistant to failure as compared to existing devices. The broader impact/commercial potential of this project are evident in that Knee Arthritis is a debilitating condition that leads to over 600,000 TKR?s per year. The TKR currently represents approximately 8% of all Medicare spending. Total hospital charges for this procedure are expected to approach $40 billion by 2012. Revision rates for TKR's are significant; 10% at 10 years and 20% at 20 years. Moreover, with an aging population, the number of TKR's and revisions is steadily increasing; of which, a majority will be completed under Medicare coverage. This project will accelerate production of an innovative device that employs state-of-the-art manufacturing processes and structural engineering design principles to substantially improve the bone/TKR implant interface. The design of the device has been optimized to address the problems associated with initial and long-term fixation and could thereby reduce or eliminate the need for revision procedures. This would benefit the healthcare economy and the quality of life for those that require knee replacement therapy. Furthermore, this project is part of an educational initiative that includes researchers at Texas A & M University that are employing this technology in providing unique educational experiences for graduate students in advancing engineering principles in medical device design.